A espécie Dekkera bruxellensis tem sido detectada como a principal levedura contaminante em diversos processos fermentativos, dentre eles o de produção de etanol combustível, apresentando uma surpreendente capacidade de crescimento e adaptação naqueles substratos. No entanto, pouco se conhece sobre suas características de crescimento em condições de estresse e comportamento fermentativo. Desta forma, este trabalho objetivou avaliar a tolerância ao estresse e as características fermentativas exibidas por três linhagens de D. bruxellensis isoladas da fermentação alcoólica, além do efeito da contaminação em mosto de caldo de cana sobre os parâmetros fermentativos, buscando informações que possam contribuir para o manejo da fermentação alcoólica quando contaminada com esta levedura. Foram realizados testes de caracterização em meio YEPD sólido e líquido em condições estressantes para as três linhagens de D. bruxellensis e uma linhagem de S. cerevisiae (PE-02). O efeito do tratamento ácido associado ao etanol sobre a viabilidade das quatro linhagens em situação de agitação e sem agitação foi também avaliado. Em seguida, testes fermentativos em meio sintético (sem reciclo celular) e em meio de caldo de cana (com reciclo celular e utilizando-se ou não tratamento ácido) foram conduzidos para verificar as características fermentativas das linhagens de D. bruxellensis em comparação com S. cerevisiae, simulando-se uma contaminação por 103 células/mL da linhagem CCA155 em meio de caldo de cana. As três linhagens de D. bruxellensis apresentaram crescimento invasivo em meio YEPD sólido, possivelmente um mecanismo de sobrevivência da levedura em condições estressantes. Observou-se uma variação na resposta das linhagens às situações de estresse (baixo pH e alta concentração de etanol). Em condições não estressantes, a linhagem PE-02 apresentou melhor desenvolvimento, no entanto, em situações de estresse de pH, concentrações de açúcar e etanol, as linhagens de D. bruxellensis desenvolveram-se melhor. O controle eficiente do crescimento destas leveduras poderia ser obtido com um tratamento combinado de baixo pH (1,5) e etanol (9%), porém houve também prejuízo significativo à levedura S. cerevisiae, embora em menor extensão. Em sistema de batelada sem reciclo celular em meio sintético, verificou-se que a agitação influenciou significativamente a produção de etanol e ácidos por D. bruxellensis. O teor alcoólico foi maior quando se utilizou glicose como fonte de carbono ao invés de sacarose. Em sistema de batelada com reciclo celular em meio de caldo de cana, foram obtidos melhores resultados quanto à produção de etanol, menor teor de açúcar redutor total residual e maior eficiência fermentativa quando se utilizou o tratamento ácido do fermento (pH 1,5), assim como melhor controle do crescimento da linhagem CCA155 quando em cultura mista com S. cerevisiae (PE-02). O tratamento ácido utilizado teve efeito não só sobre o crescimento da levedura contaminante, mas também beneficiou a levedura do processo, resultando assim na minimização do efeito da contaminante sobre a fermentação conduzida em meio de caldo de cana sob dez ciclos fermentativos de 12 horas. / The species Dekkera bruxellensis has been considered as the main contaminant yeast in several fermentative processes, including the fuel alcohol production, showing a surprising growth capacity and adaptation in those substrates. However, a little is known about their growth characteristics in stressing conditions and fermentative profile. In this context, this work aimed to evaluate the stress tolerance and fermentative characteristics exhibited by three strains of D. bruxellensis isolated from the alcoholic fermentation, besides the effect of the contamination in sugar cane juice over the fermentative parameters, searching for information that could contribute to the management of the alcoholic fermentation when the medium is contaminated with this yeast. Characterization tests in YEPD medium (solid and liquid) under stressing conditions for the D. bruxellensis and S. cerevisiae (PE-02) strains were carried out. The effect of the acid treatment associated with ethanol over the cell viability of the four strains in shaken and non-shaken flasks was also evaluated. Following, fermentative tests in synthetic medium (without cell recycle) and in sugar cane juice (with cell recycle and with/without acid treatment) were carried out to verify the fermentative characteristics of the strains of D. bruxellensis comparing to S. cerevisiae, simulating a contamination by 103 cells/mL of the strain CCA155 in sugar cane juice. All the strains of D. bruxellensis showed invasiveness in YEPD agar medium, probably a survival mechanism in stressful conditions. A variation in the response of the strains to the stressing conditions (low pH and high ethanol concentration) was observed. In nonstressing situations, the strain PE-02 showed better growth; however, in stressing conditions of pH, ethanol and sugar concentrations, the strains of D. bruxellensis had better growth performance. The effective control of their growth could be obtained with a combined treatment of low pH (1.5) and ethanol (9%), however, a significant harmful effect to the S. cerevisiae strain was also verified, but in a lower extension. In batch system without cell recycle in synthetic medium, it was verified the influence of agitation over the ethanol and acid production by D. bruxellensis. The alcohol content was significantly higher when glucose was utilized instead of sucrose. In batch system with cell recycle in sugar cane juice, the best results for ethanol production, lower residual total reducing sugar and higher fermentative efficiency were obtained with the acid treatment of the ferment at pH 1.5, as well as a better growth control of the strain CCA155, in mixed culture with S. cerevisiae (PE-02). The acid treatment utilized in this work had effect not only over the growth of the contaminant yeast, but also benefited the yeast S. cerevisiae, resulting in the minimization of the effect of the contaminant over the fermentation developed in sugar cane juice medium in 12-hour ten fermentative cycles.

Este estudo trata da criação em dança com mediação tecnológica observando os procedimentos de criação em videodança analisados pelas perspectivas do artista Gustavo Gelmini e do processo de criação da videodança “Alegoria do Veado Ferido” (2017) de minha proposição. Esta pesquisa de caráter qualitativo utiliza como estratégias metodológicas entrevistas semiestruturadas com o artista bem como o relato de experiência na criação da videodança supracitada. A discussão teórico-metodológica percorre algumas pistas do campo da dança e da comunicação para responder à principal questão que mobiliza esta investigação: como as estratégias de criação em dança com mediação tecnológica nos permitem apreender os modos de virtualização dos corpos engajados no fazer videodança? A pesquisa tem por objetivo refletir sobre a prática das danças criadas para o vídeo problematizando as questões do corpo enquanto presença, materialidade, virtualidade, bem como de suas relações com o meio. Justifica-se por buscar oferecer caminhos de compreensão para a dança na contemporaneidade, aproximando e entendendo como relacionais as incidências destes outros corpos bem como de suas virtualidades. Conclui-se na elaboração do princípio de contaminação entre corpo, dança e tecnologia como instrumento pertinente à criação em videodança. / This study deals with the creation in dance with technological mediation observing the procedures of creation in videodance analyzed by the perspectives of the artist Gustavo Gelmini and the creation process of the videodance "Allegory of the Injured Deer" (2017), of my proposition. This research of qualitative character uses as methodological strategies semi-structured interviews with the artist, as well as the report of experience in the videodance creation mentioned above. The theoreticalmethodological discussion goes through some clues in the field of dance and communication to answer the main question that mobilizes this investigation: how do dance creation strategies with technological mediation allow us to apprehend the virtualization modes of bodies engaged in videodance? The research aims to reflect on the practice of dances created for the video, problematizing the body's questions as presence, materiality and virtuality, as well as its relations with the environment. It is justified by seeking to offer ways of understanding dance in contemporaneity, approaching and understanding as relational the incidences of these other bodies as well as their virtualities. It is concluded in the elaboration of the principle of contamination between body, dance and technology as a pertinent instrument to the creation in videodance.

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The thesis deals with the contamination of the workspace with a liquid aerosol, which is generated by scattering and evaporation of the cooling fluid. Cooling fluid are primarily intended to lubricate, cool and clean the tool and the workpiece, but the unwanted side effect is the formation of a liquid aerosol that holds in the air of the workspace. In such a contaminated work environment, the operator is exposed to a certain dose of a liquid aerosol that causes dermatological and respiratory problems. The topic of the thesis was to find out the number of particles of liquid aerosol that arises under varying working conditions and its dispersion in space. This amount was determined by image analysis using a high-speed camera.

The main aim of this experimental work is to describe, based on laboratory experiments, how the change of lubricant condition affects friction and wear of the lubricated node. The changes studied will be contamination of the oil with moisture, solid particles and its oxidative degradation. For this purpose, a tribometer in a block-on-ring configuration and a back-to-back device will be used.

Brownfields are one of the unfavorable parts of industrial heritage that developed from 18th to 20th century. Brownfields are very different and in most cases they have negative impact on the environment. Crucial for this thesis were brownfields with certain level of contaminations. The site of a former refinery of mineral oils OSTRAMO, which represents ecological burden, is a brownfield that can threaten the environment in all its compartments. This was the reason why OSTRAMO was selected for this thesis. The goal of this thesis was to evaluation of ecotoxicological effects of contaminated samples taken from the location via ecotoxicity testing in aquatic and contact arrangement. The result of each test confirmed expected negative impact of the samples from the location of former rafinery on testing organisms.

A deteriorating trend has been noted in the bacteriological quality of surface irrigation water sources in South Africa. In a bid to compare the bacteriological quality of two irrigation water sources as well as whether irrigation water was a source of bacterial pathogens on irrigated lettuce, this study was designed and divided into two phases. Phase one involved determination of physico-chemical parameters and bacterial indicators in the Loskop canal, the Skeerpoort river and lettuce irrigated with water from the Skeerpoort river over 10 months. Co-currently the study further determined the diversity of the most prevalent bacterial microflora in the 3 sample sources over the same time period. Aerobic colony counts (ACC), Aerobic spore formers (ASF), Anaerobic spore formers (AnSF), Faecal coliforms (FC), Intestinal enterococci (IE) and Staphylococcus aureus (S. aureus) as well as prevalence of Escherichia coli (E. coli), Salmonella spp and Listeria monocytogenes (L. monocytogenes) were determined. Additionally the most prevalent aerobic bacterial species isolated from the three sources were determined. Higher mean rainfall was noted in areas surrounding the Skeerpoort river (74.7mm) than the Loskop canal (0.1mm). Mean temperature was 15.4˚C and 18.2˚C while mean pH was 7.4 and 8.4 in the Loskop canal and the Skeerpoort river respectively. Low mean bacterial counts of less than 3.4 log10cfu/ml, were noted for ACC, ASF, AnSF, S. aureus and IE at both irrigation sites. Higher mean ACC of 5.9 log10cfu/g and S. aureus counts of 3.0 log10cfu/g were noted on lettuce. Although low mean counts of FC (1.3 log10cfu/100ml) were noted for all three sources, high incidence of E. coli was observed during bacterial composition studies on nonselective media. This suggested underestimation of faecal contamination possibly indicating that identification of specific pathogens provided a better measure of assessing bacterial contamination than bacterial indicators. E. coli, Bacillus spp and Enterobacter spp were the most prevalent bacteria in the Loskop canal, the Skeerpoort river and on lettuce. Prevalence of E. coli, Bacillus spp and Enterobacter spp in the Loskop canal was 23%, 33% and 26% respectively. Similarly prevalence in the Skeerpoort river was 36%, 26%, 16% respectively. On lettuce prevalence of the same bacteria was 36%, 30% and 6% respectively. E. coli O157:H7 was isolated at both irrigation sites while Salmonella enterica (gp 1) ST paratyphi A was isolated from the Skeerpoort river. High prevalence of similar bacterial species within the Loskop canal and the Skeerpoort river suggested similar sources of contamination in the two water sources inspite of different geographical location and surrounding land use practices. Additionally, similar bacterial species in irrigation water from the Skeerpoort river and on irrigated lettuce suggested water as a source of contamination on produce. Additionally it suggests ability of bacterial pathogens to withstand environmental conditions under field conditions which may pose a risk to food safety and public health among individuals consuming irrigated fresh produce. Phase 2 aimed at determining the prevalence of antibiotic resistant and virulent E. coli collected from the Loskop canal, the Skeerpoort river and lettuce irrigated with water from the Skeerpoort river. Forty one (41) E. coli isolates: (19) Loskop canal; (12) the Skeerpoort river; (10) lettuce were tested with 11 antibiotics at single concentrations and screened for Shigatoxin 1 (stx 1), Shigatoxin 2 (stx 2) and intimin (eae) genes. Antibiotic resistance was also used as a means of clustering E. coli isolated from the 3 sources. In the Loskop canal 84% and 83% of strains in the Skeerpoort river were resistant to at least one antibiotic. There was a significant difference (p≤0.05) in resistance to antibiotics between isolates from the Loskop canal and the Skeerpoort river. Additionally the combined effect of isolate source (irrigation water site) and antibiotics for isolates from the Skeerpoort river was significant (p≤0.05). From lettuce, 90% of isolates were resistant to at least one antibiotic and resistance significantly differed (p≤0.05) from isolates in the Skeerpoort river. The highest resistance to single antibiotics in all three samples was to cephalothin and ampicillin. Higher resistance was noted to multiple (more than 2) antibiotics in the Skeerpoort river (33%) than Loskop canal (5%). Most isolates from the same source showed close relatedness. Close relatedness was noted between isolates from the Loksop canal (10.5%) and the Skeerpoort river (16%). From irrigated lettuce 40% of isolates showed close relatedness to isolates in irrigation water from the Skeerpoort river. In the Loskop canal 15% and 41% of isolates in the Skeerpoort river possessed virulence genes. From lettuce, 20% of isolates possessed virulence genes. In the Loskop canal as well as from lettuce all isolates with virulence genes were antibiotic resistant while 80% of isolates with virulence genes in the Skeerpoort river were antibiotic resistant. In the Loskop canal 10% and 25% of isolates in the Skeerpoort river were positive for stx1/stx2 and eae, genes synonymous with Enterohaemorrhagic E. coli (EHEC). Results from this study show that E. coli from the two irrigation water sources as well as on irrigated lettuce were resistant to antibiotics and potentially pathogenic. This may increase risk of contaminating irrigated fresh produce which may compromise food safety and public health of consumers. / Dissertation (MSc)--University of Pretoria, 2013. / gm2014 / Food Science / unrestricted

Aflatoxin is a poisonous mold that has spread around the world, posing a threat to food security and the agricultural economy. A total of 4,5 million people are in danger of being exposed to aflatoxins on a long-term basis around the world. Acute toxicity is caused by consuming significant amounts of toxins in a short period of time, which can lead to death in the worst cases, whereas chronic toxicity is caused by consuming small quantities over a longer period of time, which can lead to low birth weight, immunosuppression, restricted growth in children, and liver cancer in the worst cases. The occurrence of aflatoxins in West Africa was recognized, studied, and investigated in this paper based on a literature review. The findings demonstrate that large levels of aflatoxins have been found in West African raw materials and food and the human body. Children under the age of five, pregnant women, and breastfeeding mothers are the most vulnerable to aflatoxins. Furthermore, the findings reveal that the majority of the population is unaware of aflatoxins and its health implications. Inadequate governmental systems, low societal development, lack of access to health care, a low educated population, climate variability and climate change, high levels of illiteracy, and a lack of laboratories are only a few of the many obstacles that the region has in limiting aflatoxins concentrations. Sorting procedures, the use of tarpaulins, and seminars have all helped raise awareness and knowledge and reduce contamination and consumption of aflatoxin-contaminated foods. This study argues that a multi-sectoral strategy is needed to promote food security and local education. Increased limitations and regulations and higher standards may be able to help limit aflatoxin contamination and exposure.

INTRODUCTION: The Charlestown Sprouts Community Garden, one of Bostonʼs largest community gardens, comprises 105 plots--all producing food--located in the historic neighborhood of Charlestown. It serves mainly minority and recent immigrant member households who rely on the land as a source of fresh produce. To ensure the safety of food production at the garden, the coordinators sought assistance from the Department of Environmental Health at the Boston University School of Public Health (BUSPH) to: 1. conduct a historical survey identifying past land uses, 2. characterize potential contaminant exposures to gardeners, and 3. furnish health-protective recommendations to minimize gardener hazard exposures. In the process of meeting these aims, broader dimensions of food production in the urban environment emerged from the literature: soil safety for urban agriculture, environmental justice, food security, determining “safe” levels of contaminants in urban soil, and the expansive policy implications that these issues engendered. For the work presented in this thesis project, the scope of interrelated topics were refined and lended contextual structure for a semi-quantitative characterization of human health risk from potential soil lead (Pb) exposures. This was accomplished by employing probabilistic modeling with the USEPA's Integrated Exposure Uptake Biokinetic Model for Lead in Children (IEUBK) (2010). Under specified assumptions of multimedia Pb exposures, the model predicts a theoretical young childʼs probability of his or her lead blood concentrationʼs (PbB) exceeding a PbB cutoff. For this analysis, the recently promulgated CDC reference value of 5 μg/dL was used as a cutoff in addition to the model default of 10 μg/dL. The IEUBK was also employed to approximate a range of soil Pb concentrations that could be considered “acceptable,” based on a health-protective approach; that is, to estimate a soil Pb concentration that would not significantly contribute to the exceedance of PbB > 5 μg/dL as a result of exposures to lead in soil. In this evaluation, an acceptable soil Pb concentration is defined as a mean soil Pb concentration that is determined by consideration of minimizing human health risk and maximizing practicability of the means to achieve the soil criterion—a level that could be reasonably achieved and be safe for urban agriculture. METHODS: Research for the historical survey included, but was not limited to, consulting historical fire insurance maps, archived municipal and county records, environmental databases, geographic information systems (GIS), and gathering accounts from local community members, historical societies, and multiple Boston city agencies to build a historical narrative about the garden land and the adjacent properties. For the IEUBK model runs, multimedia exposure parameter values from Boston environmental data (air, water, and soil) were used as inputs for the IEUBK modeling runs in the absence of suitable site-specific data. Comparison runs were executed with soil Pb concentration data from compost sourced from the City of Boston Department of Public Works Leaf and Yard Waste composting program and from Boston-area private compost facilities. RESULTS AND CONCLUSIONS: The garden was established at a site with a varied history of land uses from rail yard, to salt plant, to unknown activities. Community-member accounts, corroborated by photointerpretation data, suggest that the site was possibly an dumping grounds in the 1970ʼs-80ʼs. Based on the findings of the survey, it is likely that a number of potential contaminants exist at the garden, including lead, arsenic and/or polyaromatic hydrocarbons (PAHs). Based on visual inspection, point-source contamination of the soil is likely to be occurring at the garden, stemming from the treated rail ties that compose a majority of the garden plot constructions and of the plots inspected, the timbers appeared to be CCA-treated wood. The accumulation of site-specific knowledge gained through historical research, (GIS), and anecdotal evidence aided in determining what historical hazards were likely to pose a current risk to gardeners through gardening activities. The IEUBK model predicted a geometric mean blood value of 2.73 μg/dL with an associated risk of a young childʼs PbB exceeding 5 ug/dL as 9.9% using default parameter values. In comparison, to achieve a goal of less than 5% risk, the IEUBK modeling indicated that soil Pb would have to be less than 153 mg/kg. Under the guidance of BUSPH faculty, the findings and consequent recommendations, differing in remediation technique and resource-intensiveness, were summarized in a document for the garden steering committeeʼs development of imminent renovation plans.